1. Field of the Invention
The present invention relates to a non-fogging antireflection film, an optical member employing the film, and a process for producing the film.
2. Related Background Art
Many optical members such as lenses, mirrors, and prisms are required not to be reflective. The treatment for antireflection is conducted generally by forming an antireflection film on the surface of a base material such as a lens. However, no antireflection film is known to be effective for prevention of fogging of optical members.
The fogging of the optical member such as lenses and mirrors is caused by deposition of moisture in a form of fine water droplets from the air onto the surface of the optical member when the temperature of the surface becomes lower than the dew point of the surrounding air, resulting in irregular reflection of light on the surface of the optical member. Therefore, the fogging can be avoided by preventing the condensation of water droplets onto the optical member. Conventionally, the antireflection film has a thickness of not more than 1 .mu.m, and does not exhibit satisfactory non-fogging property.